Chronological age-related metabolome responses in the dinoflagellate Karenia mikimotoi, can predict future bloom demise

Abstract

Karenia mikimotoi is a common harmful algal bloom (HAB)-forming dinoflagellate and has caused severe financial loss in aquaculture. There are limited metabolomic studies on dinoflagellate biology. Here, we examined alterations in metabolic profiles over the growth curve of K. mikimotoi under nitrogen or phosphorus deficiency and further explored a key criterion for the diagnosis of late stationary phase to identify when the dinoflagellate cells will enter bloom demise. The results demonstrate the differential expression of metabolites for coping with chronological aging or nutrient deprivation. Furthermore, an increase in the glucose to glycine ratio in the late stationary phase was indicative of dinoflagellate cells entering bloom demise; this was also detected in the cultured diatom, Chaetoceros tenuissimus, indicating that this may be the general criterion for phytoplankton species. Our findings provide insights regarding chronological aging and the criterion for the prediction of phytoplankton bloom demise.

Revealing the algicidal characteristics of Maribacter dokdonensis: An investigation into bacterial strain P4 isolated from Karenia mikimotoi bloom water

“…This suggests that the effect of growth phases varied between bacterial species. More, K. mikimotoi in the stationary phase had higher glucose content than that in the log phase (Hano & Tomaru, 2023). Glucose has been observed to induce the cytotoxicity of algicidal bacteria Citrobacter sp.…”